Cycle.



W. DOUGLAS.

CYCLE.

APPLICATION FILED 1AN.22. 191s.

Patented July 16, 1918.

3 SHEETS SHEET l W. DOUGLAS.

CYCLE.

APPLICATION HLED JAN. 22, l9l8.

Patented Jul 16, 1918.

Pnomuma. vusunmmn. o. c

W. DOUGLAS.

CYCLE.

APPLICATION FILED 1Au.22.1918.

Patented July 16, 1918.

3 SHEETS-SHEET 3.

ml gm;

WILLIAM DOUGLAS, F BRISTOL, ENGLAND.

CYCLE.

Specification of Letters Patent.

Patented July 16, 1918.

Application filed January 22, 1918. Serial No. 213,247.

To all whom it may concern:

7 subject of the King of England, residing at Bristol, in Englanchhave invented certain new and useful Improvements in Cycles, of which the following is a specification.

This invention relates to improvements in spring frames for cycles, of the kind in which the back fork frame is pivoted to the lower part of the main frame, and one or more links are pivoted to the upper part of the main frame and to the back fork frame so as to form with'the latter a toggle having an angle of nearly 180. A feature of the present invention is that a shock absorber is operatively connected between the main frame and a point intermediate the ends of said links. I

Several embodiments of the invention are illustrated in the accompanying'drawings said shock absorber,

Fig. 4 is a section showing a modified construction of shock absorber,

' Fig. 5 is a section of a further modification, and, r

Fig. 6 is a plan of the carrier shown in Fig. 1. I

A is a back fork frame pivoted at B to the lower part of the main frame of which C is a lower horizontal member, D is the seat pillar, andE is an upper horizontal member. F are toggle links connecting the back fork frame to the upper part of the main frame and supporting the former laterally. A carrier platform G is supported on struts H connected between the rear end of the platform and the pivot B, while tie members I connect the platform to a lug J on the upper part of the seat pillar D. The toggle links F are pivoted at K to bosses Q on the back fork frame (see Fig. 3), and are pivoted at L to the upper part of the seat pillar D through short connecting links M. A shock absorber spring N is pivoted intermediate the ends of each link F and is connected at the other end to the member E of the main frame.

. Bosses 0 (see Fig. 3) extend on each side of the seat pillar D and the connecting links M are pivoted thereto. A pin P connects the other ends of the connecting links to the upper ends of the toggle links F. Each spring N is held at one end by a plug'R pivoted to a toggle link F, and at the other end by a plug S connected to a clamp T on the member E. Each spring N is adapted to act both in tension and compression.

Instead of employing the connecting links M, the toggle links F can be pivoted'in a rubber bushing in the upper part of the main frame so as to provide for the slight vertical movement of the toggle links which takes place when the ba'ck'fork frame oscillates on its pivot. Instead of employing a rubber bushing, the toggle links can be pivoted eccentrically on a pin carried on the main frame in an ordinary bushing.

Referring to the modified construction illustrated in Fig. 4, an auxiliary spring U is provided and is adapted to act only in compression, and when heavy loads are imposed on the mechanism. 7 This spring U is carried on an auxiliary plug V which is connected to the plug S by a nut W, the plug S being held on the clamp T by a nut X.

In Fig. 5 an additional auxiliary spring U is shown-which can act only in compression. This spring U is carried on a rod Y which passes freely through the plu S- which is screwed'into the clamp ,T an earries the springs N and Uand is screwed into the plug R. The compression spring U comes into operation only when the spring N has been to some extent subjected to tension. .Theconstructions illustrated in Figs. 4 and 5 provide a light spring effect for light loads, while the auxiliary springs afford additional supportwhen heavy loads are imposed on the mechanism.

That I claim as my invention and desire to secure by Letters Patent is 1. In a cycle frame the combination of a main frame, a back fork frame pivoted to the lower part of said main frame, links pivoted to the upper part of said main frame and to said back fork frame so as to form with the latter a toggle having an angle of nearly 180, a shock absorber operatively connected between said main frame and a point intermediate the ends of said links, a rear carrier platform, struts connected to said platform and to the lower part of said main frame where pivoted to said back fork frame, and tie members connecting said platform with the upperpart of said main frame. L

2. In a cycle frame the combination of a main frame, a back fork frame pivoted to the.

lower part of said main frame, links pivoted to the upper-part ofsaid main frame and.

to said back fork frame so as to form with the latter a toggle having'air'a ngle of nearly 180? a cylindrical helical spring operatively connected between said mainframe and a point interihediatfe the endsof said links, a rear carrier platform, struts connected to said 1'3'latfor-m a n d to the lower part of said main frame Where pivotedte 'saiol back fork frame, and tie members connectingsaidplatform 'ivith the upper part of said main frame;

'3. Ina cycle framethecombination of a main frame, a back fork frame'plvoted to operatively"connected to one end of the first.

I named'spring' and adapted t'o b'e compressed after the first named spring has been stressed to some ;extent, a rear carrier platform,

struts eon eaea to said platform and to the lower part of said main frame Where pivoted to saidbac'k fork "frame, and'tie members connecting said platform with the upper part of said main frame.

e. Ina cyclev frameth'e'combination of a mainframe, a back fork frame pivotedto the lo"Wer. part o'f'said main frame, links pivoted to the u per part of: said main frame and .to said back fork'franie' so [as to 7 form with the latter a to'gglehaving an angle of nearly 180, a" cylindrical helical spring 'operatively connected between said main frameand'a point lntermedlate the ends. of said links, anauxiliary cylindrical helical spring shorter than the first named spring 'Withinivhich it is located axially and toone end of which itisoperativelyconnected, a rear carrier platfor'm, struts connected to said platform and to the lower angle of nearly 180, a cylindrical helical spring operatively connected between said main frame and "a point intermediate the ends of said links, a'rod operatively con; nected to one end of said-s'pring and passing axially 'therethrough, an auxiliarycylindrical helical "spring operativ'ely connected axially on the outer end of saidrod, a rear carrier platform, struts connected to said platform 'andto the lower part ofsaidmain frame Where pivoted to'said b ac'k'forkframe, and tie members connecting said; platform with the upper part ofv said'maih ffranie 6. In a cycle framethe'-conibin'ation of a ma'in frame,a back fork frame pivoted to the loiver part Cfsaid 'n'i'ain nam links pivoted to the upper part of"said main frame-and to said -back fork frame 'so as'to form with the latter "a teg lefhaving an angle of nearly 180", a'cyli'nd'rical helical spring operatively connected between said mam frame an'da point lntermed ate the endsof said links,.a rodoperatively coi1-* nee/ted to one endof said-spring and/passing axially therethro-ugh, an auxiliary cylindrical helical spring o-peratively connected axially on the outer end of said rodg' lascond auxiliary "cylindrical helical spring 'short'er than the first nam'edisp ring i vithin which it is located axially and tooneen'd'of which it is operatively connected, a rear "car'rie'r platform, struts connected to said platform and to the lower part of said main fraine who're pivot-edto saitlbackifork frame, and tie members connecting said platform with the; upper part o fsaid mai'n'frame. v .y

- In testimony vvhereof I' have signed. my

name to this s1 ecificatio'n in the presence "of two subscribingwvitnesses; 1 V \VILLTAM DOUGLAS, 1 itnes'sesz I G. JLBAU i I, I JOHNS. ARMSTRONG,

' Copies 6! this patent may beiibtained forfivecents eath, by adfirssing the cominissioner ofPatents.

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